I tried a 20 MB/s Ultra in my T4i and it was a DOG compared to these cards. My camera felt very sluggish.

Yeah, up to. They picked that wording for a reason. They're not lying because the read speed does go up to 45, but not the write, especially not in the T4i. And we weren't talking about the 20 MB/sec Ultra cards but the 30 MB/sec ones.

Yes, the only write speeds that are important here are the ones that have been measured in the T4i itself. My results are posted above (35 MB/s and 40 MB/s). You are welcome to post your own. In fact, that would actually be helpful.